pISSN : 1598-706X / eISSN : 2288-8381
한국주조공학회지 (36권5호 159-166)
Evolution of Microstructure and Mechanical Properties of a Ni Base Superalloy during Thermal Exposure
니켈기 초내열합금의 열간노출에 따른 미세조직 및 기계적 특성 변화
In-Soo Kim†, Baig-Gyu Choi, Joong-Eun Jung, Jeong-Hyeon Do, In-Yong Jung and Chang-Yong Jo
High tmeperature Materials Department, Kora Institute of materials Science
The microstructural evolution of a cast Ni base superalloy, IN738LC, has been in investigated after long term exposure at several temperatures. Most of the fine se secondary investigated after long term exposure at several temperatures. Most of the fine secondary γ' particles resolved after 2000 hour exposure at 816˚C. At higher temperatures of 871˚C and 927˚C, secondary γ' resolved after 1000 hours of exposure, and cuboidal primary γ' grew with exposure time. During the thermal exposure, σ phase formed at all tested temperatures, and η phase was observed around interdendritic regions due to carbide degeneration. The influence of microstructural evolution during thermal exposure on the mechanical properties has been analyzed. The effects of γ' particle growth are more pronounced on the high temperature creep properties than on the room temperature tensile properties.
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